He's probably also taking one while he sits on that thing.
To recap, Thanos has been with us since the first Avengers, in which he gave Loki a magic scepter to go to Earth and retrieve the Tesseract, a magic interdimensional box that happens to contain one of the six Infinity Stones that Thanos needs to rule the universe or to finally bang Death (seriously!) or whatever. It's insanity. Anyway, we later find out in Avengers: Age Of James Spader that the scepter Thanos gave Loki had an Infinity Stone inside it the whole time.
It's like a nesting doll of MacGuffins.
This means one of two things: Either Thanos was too dense to know that he already had one of the Stones in his possession or he willingly gave it away to Loki -- the god of deceit -- to run an errand for him that he easily could have done himself. But Loki gets captured, the scepter gets cracked open, and the stone is shoved into Vision's forehead. And so Thanos goes from having one Stone to zero Stones, PLUS a brand-new magic British android who wants to kick his ass. But hey, live and learn -- right?